Terminal, base station, communication method, and integrated circuit

ABSTRACT

There are provided a terminal, a base station, a communication method, and an integrated circuit for enabling the base station and the terminal to efficiently perform received power measurement and perform a measurement report in a communication system in which the base station and the terminal perform communication with each other. The terminal that performs communication with the base station, includes a reception unit  205  that performs received power measurement that is based on a first signal in a certain cell, in which in a case where a configuration of a second signal is set and the certain cell is not set to a predetermined carrier type, the reception unit  205  performs the received power measurement that is based on the first signal, and in a case where the certain cell is set to the predetermined carrier type, the reception unit  205  performs the received power measurement that is based on the second signal.

TECHNICAL FIELD

The present invention relates to a terminal, a base station, acommunication method, and an integrated circuit.

BACKGROUND ART

In communication systems approved by the Third Generation PartnershipProject (3GPP), such as Wide Code Division Multiple Access (W-CDMA),Long Term Evolution (LTE), and LTE-Advanced (LTE-A), or in communicationsystems approved by the Institute of Electrical and ElectronicsEngineers (IEEE), such as Wireless LAN and Worldwide Interoperabilityfor Microwave Access (WiMAX), a base station (a cell, a transmissionstation, a transmission apparatus, or an eNodeB) and a terminal (amobile terminal, a reception station, a mobile station, a receptionapparatus, user equipment (UE)) each include multiple transmit andreceive antennas, space-multiplex a data signal, and realize high-speeddata communication by using Multi Input Multi Output (MIMO) technology.

In the communication system, in order to realize the data communicationbetween the base station and the terminal, the base station needs toperform various control processes on the terminal. For this reason, thebase station notifies the terminal of control information using apredetermined resource, and thus performs the data communication indownlink and uplink. For example, the base station notifies the terminalof resource allocation information, modulation information on and codinginformation on the data signal, information on the number of spacemultiplexing of the data signal, transmission power control informationand the like, and thus realizes the data communication. For these piecesof control information, a method disclosed in NPL 1 can be used.

The communication system corresponds to at least Time Division Duplex(TDD). LTE that employs a TDD scheme is also referred to as TD-LTE orLTE TDD. TDD is a technology that makes full duplex communicationpossible in a single frequency band by performing timedivision-multiplexing on an uplink signal and a downlink signal.

The communication system is a cellular communication system which iscellularly-divided for multiple areas covered by the base station.Furthermore, a single base station may manage multiple cells.Furthermore, a single base station may manage multiple remote radioheads (RRH). Furthermore, a single base station may manage multiplelocal areas. Furthermore, a single base station may manage multipleheterogeneous networks (HetNet).

In the communication system, the terminal can measure at least referencesignal received power (RSRP) based on a cell-specific reference signal(CRS) (NPL 1).

In the communication system, communication may be performed using acarrier (component carrier) in which a part of physical channels orsignals is not arranged. Here, such a carrier is referred to as a newcarrier type (NCT). For example, a cell-specific reference signal, aphysical downlink control channel, or a synchronization signal (aprimary synchronization signal or a secondary synchronization signal)may not be arranged in the new carrier type. Furthermore, it has beenconsidered that the Physical Discovery Channel (PDCH) for performingmobility measurement and time/frequency synchronization detection beintroduced in a cell for which the new carrier type is set (NPL 2).Moreover, in some cases, the new carrier type is also referred to as anadditional carrier type (ACT).

CITATION LIST Non-Patent Literature

NPL 1: 3rd Generation Partnership Project Technical Specification GroupRadio Access Network; Evolved Universal Terrestrial Radio Access(E-UTRA); Physical layer; Measurements (Release 10) 30 Mar. 2011,TS36.214 v10.1.0 (2011-03).

NPL 2: “Issues Regarding Additional Carrier Type in Rel-11 CA”,R1-114071, 3GPP TSG-RAN WG1 Meeting #67, San Francisco, USA, 14-18 Nov.2011.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, the measurement of received power using a signal fortime/frequency synchronization detection is not disclosed. Moreover, ameasurement method for use in a terminal in a case where the receivedpower measurement of a specific signal is not performed is notdisclosed.

The present invention is made in view of the situation and an object ofthe present invention is to provide a terminal, a base station, acommunication method, and an integrated circuit for enabling the basestation and the terminal to efficiently perform received powermeasurement in a communication system in which the base station and theterminal perform communication with each other.

Means for Solving the Problems

(1) To accomplish the object, the present invention provides thefollowing means. That is, according to the present invention, there isprovided a terminal that performs communication with a base station,including: a reception circuitry that performs received powermeasurement that is based on a first signal in a certain cell, in whichin a case where a configuration of a second signal is set, if thecertain cell is not set to a predetermined carrier type, the receptioncircuitry performs the received power measurement that is based on thefirst signal, and if the certain cell is set to the predeterminedcarrier type, the reception circuitry performs the received powermeasurement that is based on the second signal.

(2) Furthermore, in the terminal according to the present invention, inthe case where the configuration of the second signal is set, if thecertain cell is not set to the predetermined carrier type, the receptioncircuitry may perform the received power measurement that is based onthe second signal.

(3) Furthermore, in the terminal according to the present invention, inthe case where a configuration of a third signal is set, the receptioncircuitry may perform the received power measurement that is based onthe third signal, regardless of a carrier type of the certain cell.

(4) Furthermore, in the terminal according to the present invention, ina case where the cell that is set to the predetermined carrier type isdeactivated, the reception circuitry may perform the received powermeasurement that is based on the second signal, based on a firstmeasurement period, and in which in a case where the cell that is set tothe predetermined carrier type is activated, the reception circuitry mayperform the received power measurement that is based on the secondsignal, based on a second measurement period.

(5) Furthermore, in the terminal according to the present invention,when a predetermined measurement time that is configured from the firstmeasurement period elapses, the reception circuitry may report to ahigher layer a result of the measurement of the received power that isbased on the second signal.

(6) Furthermore, in the terminal according to the present invention, ina case where the received power that is based on the second signal ismeasured based on the second measurement period, when a predeterminedmeasurement report event is fulfilled, the reception circuitry mayreport to a higher layer the result of the measurement of the receivedpower for the second signal.

(7) Furthermore, according to the present invention, there is provided abase station that performs communication with a terminal, including: atransmission circuitry that transmits to the terminal informationrelating to a configuration of a second signal and information relatingto a predetermined carrier type.

(8) Furthermore, in the base station according to the present invention,the transmission circuitry may transmit to the terminal informationrelating to a measurement report event with respect to the secondsignal.

(9) Furthermore, in the base station according to the present invention,the transmission circuitry may transmit to the terminal informationrelating to a first measurement period and information relating to asecond measurement period with respect to a cell that is set to thepredetermined carrier type.

(10) Furthermore, according to the present invention, there is provideda communication method for use in a terminal that performs communicationwith a base station, the method including: performing received powermeasurement that is based on a first signal in a certain cell;performing the received power measurement that is based on the firstsignal, if the certain cell is not set to a predetermined carrier type,in a case where a configuration of a second signal is set; andperforming the received power measurement that is based on the secondsignal, if the certain cell is set to the predetermined carrier type.

(11) Furthermore, the communication method according to the presentinvention may further perform, by a higher layer, the received powermeasurement that is based on the second signal, if the certain cell isset to a predetermined carrier type, in the case where a configurationof the second signal is set.

(12) Furthermore, according to the present invention, there is provideda communication method for use in a base station that performscommunication with a terminal, the method including: transmitting to theterminal information relating to a configuration of a second signal andinformation relating to a predetermined carrier type.

(13) Furthermore, according to the present invention, there is providedan integrated circuit that is mounted in a terminal that performscommunication with a base station, the circuit causing the terminal toperform: a function of performing received power measurement that isbased on a first signal in a certain cell; a function of performing thereceived power measurement that is based on the first signal, if thecertain cell is not set to a predetermined carrier type, in a case wherea configuration of a second signal is set; and a function of performingthe received power measurement that is based on the second signal if thecertain cell is set to the predetermined carrier type.

(14) Furthermore, in the integrated circuit according to the presentinvention, in the case where the configuration of the second signal isset, if the certain cell is not set to the predetermined carrier type,the terminal may be caused to perform a function of performing thereceived power measurement that is based on the second signal.

(15) Furthermore, according to the present invention, there is providedan integrated circuit that is mounted in a base station that performscommunication with a terminal, the circuit causing the base station toperform a function of transmitting to the terminal information relatingto a configuration of a second signal and information relating to apredetermined carrier type.

When this is done, the received power measurement can be efficientlyperformed.

EFFECTS OF THE INVENTION

According to the present invention, the received power measurement canbe efficiently performed in the communication system in which the basestation and the terminal perform communication with each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram illustrating a configuration of abase station 1 according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram illustrating a configuration of aterminal 2 according to the first embodiment of the present invention.

FIG. 3 is a schematic block diagram illustrating a procedure formeasuring received power of the terminal 2 according to each embodimentof the present invention.

FIG. 4 is a schematic block diagram illustrating a received powermeasurement subframe of the terminal 2 according to a third embodimentof the present invention.

MODE FOR CARRYING OUT THE INVENTION

(Physical Channel)

A physical channel (or a physical signal) in LTE and LTE-A is described.A channel means a medium that is used in signal transmission. A physicalchannel means a physical medium that is used in the signal transmission.There is a likelihood that in LTE and LTE-A, a physical channel will beadded from now on or a structure or format type of the physical channelwill be changed or added, but in such a case, the addition and change donot have an effect on a description of each embodiment of the presentinvention.

In LTE and LTE-A, physical channel scheduling is managed using a radioframe. One radio frame is 10 ms, and one radio frame consists of 10subframes. Moreover, one subframe consists of 2 slots (that is, one slotis 0.5 ms). Furthermore, the scheduling for allocation of the physicalchannels is managed using a resource block as a minimum unit. Theresource block is defined by a given frequency domain that consists of aset of multiple subcarriers (for example, 12 subcarriers) along afrequency axis and by a domain that consists of given transmission timeintervals (one slot, or 7 symbols).

A synchronization signal consists of 3 types of primary synchronizationsignals (PSS) and a secondary synchronization signal (SSS) that isconfigured from 31 types of codes which are alternately arranged in thefrequency domain, and frame timing for radio synchronization with 504cell identities (PCI: Physical layer Cell Identify, Physical CellIdentity, or Physical Cell Identifier) by which to identify basestations is indicated by a combination of the primary synchronizationsignal and the secondary synchronization signal. A terminal 2 specifiesa cell identity of the synchronization signal received through cellsearching.

A Physical Broadcast Channel (PBCH) is transmitted for the purpose ofnotifying a control parameter (broadcast information or systeminformation) that is commonly used in the terminals within a cell. Forthe broadcast information that is not notified on the PBCH, a radioresource is notified on the PDCCH, and a layer 3 message (systeminformation) is transmitted on the PDSCH. A cell global identifier (CGI)indicating an identifier dedicated to a cell, a tracking area identifier(TAI) managing an area for waiting due to paging, random accessconfiguration information (a transmission timing timer and the like),shared radio resource configuration information and the like arenotified as the broadcast information.

A downlink reference signal is classified by its usage into multipletypes. For example, a cell-specific reference signal (CRS) is a pilotsignal that is transmitted with predetermined power for every cell, andis a downlink reference signal that is periodically repeated in afrequency domain and a time domain based on a predetermined rule. Theterminal 2 measures reception quality for every cell by receiving thecell-specific reference signal. Furthermore, the terminal 2 uses adownlink cell-specific reference signal as a physical downlink controlchannel that is transmitted at the same that time the cell-specificreference signal is transmitted, or also as a reference signal fordemodulation of a Physical Downlink Shared Channel. A sequence that isidentifiable for every cell is used as a sequence that is used in thecell-specific reference signal. The sequence may be generated with apseudo-random sequence. Furthermore, the sequence may be generated witha Zadoff-Chu sequence.

Furthermore, the downlink reference signal is used also in downlinkchannel fluctuation estimation. The downlink reference signal that isused in the channel fluctuation estimation may be also referred to as achannel state information reference signal (CSI-RS) or a CSI referencesignal. Furthermore, the downlink reference signal that is dedicatedlyset for every terminal is referred to as a UE specific reference signal(UERS) or a dedicated RS, or a downlink demodulation reference signal(DL DMRS); and is used in demodulation of the physical downlink controlchannel or the physical downlink shared channel.

The physical downlink shared channel (PDSCH) is used to transmitdownlink data. Furthermore, the physical downlink shared channel is usedto notify the terminal 2 of the broadcast information (systeminformation) that is not notified through paging or on the physicalbroadcast channel. Radio resource allocation information of the physicaldownlink shared channel is indicated with the physical downlink controlchannel.

The physical downlink control channel (PDCCH) is transmitted with thefirst several OFDM symbols at each subframe, and is used for the purposeof indicating to the terminal 2 resource allocation information inaccordance with the scheduling by the base station or an amount ofadjustment for an increase or a decrease in transmission power. Theterminal 2 monitors the physical downlink control channel that isdestined for itself before transmitting and receiving the layer 3message (paging, handover command, or the like) and receives thephysical downlink control channel that is destined for itself. Thus, theterminal 2 needs to acquire from the physical downlink control channelthe resource allocation information that is referred to as an uplinkgrant at the time of the transmission and as a downlink grant (alsoreferred to as a downlink assignment) at the time of the reception.Moreover, in addition to being transmitted with the OFDM symbol(s)described above, it is possible that the physical downlink controlchannel may be configured to be transmitted with a domain of theresource block that is dedicatedly allocated from the base station 1 tothe terminal 2. In some cases, the physical downlink control channelthat is transmitted with the domain of the resource block which isdedicatedly allocated from the base station 1 to the terminal 2 is alsocalled an enhanced physical downlink control channel (enhanced PDCCH(ePDCCH)). Furthermore, in some cases, the PDCCH that is transmittedwith the OFDM symbol(s) described above is also referred to as a firstcontrol channel. Furthermore, in some cases, the ePDCCH is also referredto as a second control channel.

A physical uplink shared channel (PUSCH) mainly uplink data and uplinkcontrol data, and it is possible that the physical uplink shared channel(PUSCH) also contains control data, such as down link reception quality,ACK/NACK, or the like. Furthermore, in addition to the uplink data, thephysical uplink shared channel (PUSCH) is used also for notifying thebase station 1 of uplink control information. Furthermore, as is thecase with downlink, the resource allocation information of the physicaluplink shared channel is indicated with the physical downlink controlchannel.

The physical uplink control channel (PUCCH) is used for sending anacknowledgement/negative acknowledgement (ACK/NACK) of data that istransmitted on the physical downlink shared channel, for notifyingdownlink channel information (downlink channel state information) andfor making a scheduling request (SR) that is an uplink resourceallocation request (radio resource request). The channel stateinformation (CSI) includes a channel quality indicator (CQI), aprecoding matrix indicator (PMI), a precoding type indicator (PTI), anda rank indicator (RI). In some cases, each indicator is expressed as anindication, the indicator and the indication have the same applicationand meaning.

Uplink reference signals include a demodulation reference signal (DMRS)and a sounding reference signal (SRS), the DMRS is used by the basestation to demodulate the physical uplink control channel the PUCCHand/or the physical uplink shared channel the PUSCH, and the SRS ismainly used by the base station to estimate an uplink channel state.Furthermore, there are two types of sounding reference signal: aperiodic sounding reference signal (Periodic SRS (P-SRS)) and anaperiodic sounding reference signal (Aperiodic SRS (A-SRS)). In somecases, the uplink reference signal is also referred to as an uplinkpilot signal or an uplink pilot channel. Furthermore, in some cases, theperiodic sounding reference signal is also referred to as a periodicsounding reference signal or a trigger type 0 sounding reference signal.Furthermore, in some cases, the aperiodic sounding reference signal isalso referred to as an aperiodic sounding reference signal or a triggertype 1 sounding reference signal. Moreover, in coordinatedcommunication, the aperiodic sounding reference signal can be dividedinto a signal specific to uplink channel estimation and a signal that isused for correcting a downlink channel state (a CQI, a PMI, or a RI).

A physical random access channel (PRACH) is a channel that is used fornotifying a preamble sequence and has a guard time. The preamblesequence may be configured to prepare 64 types of sequences to express6-bit information. The physical random access channel is used as meansby which the terminal has access to the base station 1. The terminal 2uses the physical random access channel in order to make a request tothe base station 1 for the radio resource when the physical uplinkcontrol channel is not set or to make a request to the base station 1for transmission timing adjustment information (also referred to astiming advance (TA)) indispensable in matching uplink transmissiontiming to a base-station reception timing window.

Specifically, the terminal 2 transmits the preamble sequence using theradio resource for the physical random access channel that is set by thebase station. The terminal 2 that receives the transmission timingadjustment information sets the transmission timing timer that countsthe effective time of the transmission timing adjustment informationthat is set to be shared by the broadcast information (or is dedicatedlyset with the layer 3 message), and manages an uplink state as atransmission timing adjustment state during the effective time of thetransmission timing timer (while the counting is in progress) and as atransmission timing non-adjustment state (a state where the transmissiontiming is not adjusted) during the non-effective time (after thetransmission timing timer expires). The layer 3 message is a controlplane message that is exchanged with a RRC (radio resource control)layer between the terminal 2 and the base station 1, and is used as amessage that has the same meaning as RRC signaling or an RRC message.Moreover, detailed descriptions of other physical channels are omittedbecause they have no relationship with each embodiment of the presentinvention. Furthermore, in some cases, the RRC signaling is alsoreferred to as higher layer signaling or dedicated signaling. Moreover,in some cases, the RRC signaling is also referred to as the RRC message.

(First Embodiment)

A first embodiment of the present invention will be described below. Acommunication system according to the first embodiment includes aprimary base station (also referred to as a macro base station, a firstbase station, a first communication apparatus, a serving base station,an anchor base station, a master base station, a macro cell, a firstcell, or a primary cell) as the base station 1 (hereinafter alsoreferred to as a base station apparatus, a transmission apparatus, acell, a serving cell, a transmission station, a transmission point, atransmission antenna group, a transmission antenna port group, or aneNodeB). Moreover, the communication system according to the firstembodiment may include a secondary base station (also referred to as aremote radio head (RRH), a remote antenna, a forward-extending antenna,a distributed antenna, a reference point, a low power node (LPN), amicro base station, a pico base station, a femto base station, a smallbase station, a local area base station, a phantom base station, a homeeNodeB, a second base station apparatus, a second communicationapparatus, a coordinated base station group, a coordinated base stationset, a coordinated base station, a micro cell, a pico cell, a femtocell, a small cell, a phantom cell, a local area, a second cell, and asecondary cell). Furthermore, the communication system according to thefirst embodiment includes the terminal 2 (hereinafter also referred toas a mobile station, a mobile station apparatus, a terminal apparatus, amobile terminal, a receiving apparatus, a reception point, a receivingterminal, a third communication apparatus, a receive antenna group, areceive antenna port group, or user equipment (UE)). Here, the secondarybase station 1 may be indicated as multiple secondary base stations. Forexample, the primary base station and the secondary base station mayperform communication with the terminal 2 using a heterogeneous networkarrangement, with some or all portions of a coverage of the secondarybase station being included in a coverage of the primary base station.

In some cases, in downlink transmission, the base station 1 is alsoreferred to as a transmission point (TP). Furthermore, in some cases, inuplink transmission, the base station 1 is also referred to as areception point (RP). Furthermore, a downlink transmission point and anuplink reception point are path loss reference points (reference points)for measurement of downlink path loss. Furthermore, the reference pointfor the measurement of the downlink path loss may be set independentlyof the transmission point or the reception point.

Furthermore, the small cell, the phantom cell, or the local area cellmay be set as a third cell. Furthermore, the small cell, the phantomcell, or the local area cell may be re-set as a primary cell.Furthermore, the small cell, the phantom cell, or the local area cellmay be re-set as a secondary cell. The small cell, the phantom cell, orthe local area cell may be re-set as a serving cell.

FIG. 1 is a schematic block diagram illustrating a configuration of thebase station 1 according to the present invention. As illustrated, thebase station 1 may be configured to include a higher layer processingunit 101, a control unit 103, a reception unit 105, a transmission unit107, a channel measurement unit 109, and a transmit and receive antenna111. Furthermore, the higher layer processing unit 101 may be configuredto include a radio resource control unit 1011, a measurement settingunit 1013, and a transmission power setting unit 1015. Furthermore, thereception unit 105 may be configured to include a decoding unit 1051, ademodulation unit 1053, a demultiplexing unit 1055 and a radio receptionunit 1057. Furthermore, the transmission unit 107 may be configured toinclude a coding unit 1071, a modulation unit 1073, a multiplexing unit1075, a radio transmission unit 1077 and the downlink reference signalgeneration unit 1079.

The higher layer processing unit 101 performs processing of a mediumaccess control (MAC) layer, a packet data convergence protocol (PDCP)layer, a radio link control (RLC) layer, and a radio resource control(RRC) layer.

The radio resource control unit 1011 that is included in the higherlayer processing unit 101 generates information that is arranged in eachchannel for downlink, or acquires such information from a higher node,and outputs the generated or acquired information to the transmissionunit 107. Furthermore, the radio resource control unit 1011 allocatesthe radio resource in which the terminal 2 arranges the physical uplinkshared channel (PUSCH) that is uplink data information, out of an uplinkradio resource. Furthermore, the radio resource control unit 1011determines the radio resource in which the physical downlink sharedchannel (PDSCH) that is downlink data information is arranged, fromdownlink radio resources. The radio resource control unit 1011 generatesdownlink control information indicating the allocation of the radioresource and transmits the generated downlink control information to theterminal 2 through the transmission unit 107. When the radio resource inwhich the PUSCH is arranged is allocated, the radio resource controlunit 1011 preferentially allocates the radio resource that has goodchannel quality, based on a result of uplink channel measurement that isinput from the channel measurement unit 109. To be more precise, theradio resource control unit 1011 assigns pieces of information relatingto configurations of various downlink signals and pieces of informationrelating to configurations of various uplink signals to a certainterminal or to a certain cell. Furthermore, the radio resource controlunit 1011 assigns information relating to a configuration of a firstsignal and information relating to a configuration of a second signal toa certain terminal or to a certain cell. The pieces of informationrelating to these types of configurations are generated and are outputto the transmission unit 107. Here, information relating to an n-thsignal (n is a natural number) may be set.

The measurement setting unit 1013 that is included in the higher layerprocessing unit 101 generates information relating to a measurementconfiguration, information relating to a measurement objectconfiguration, information relating to a reporting configuration,information relating to a measurement reporting configuration,information relating to a CQI reporting configuration, and outputs thesepieces of information to the transmission unit 107.

The higher layer processing unit 101 generates control information inorder to perform control of the reception unit 105 and of thetransmission unit 107, based on the uplink control information (UCI)that is notified on the physical uplink control channel (PUCCH) from theterminal 2, and a buffer situation notified from the terminal 2 orvarious pieces of configuration information on each of the terminals 2,which are set by the radio resource control unit 1011, and outputs thegenerated control information to the control unit 103. Moreover,included in UCI is at least one among an Ack/Nack, a channel qualityindicator (CQI), and a scheduling request (SR).

The transmission power setting unit 1015 sets the transmission power ofeach of the PRACH, the PUCCH, the PUSCH, the P-SRS, and the A-SRS.Specifically, the transmission power setting unit 1015 sets thetransmission power of the terminal 2 in such a manner that the PUSCH andthe like satisfy predetermined channel quality, considering interferencewith the adjacent base station 1, according to information indicating anamount of interference from an adjacent base station 1, informationindicating an amount of interference that is notified from the adjacentbase station 1 and that is given to the adjacent base station 1, channelquality being input from the channel measurement unit 109, or the like,and transmits information indicating the configuration to the terminal2, through the transmission unit 107.

Specifically, the transmission power setting unit 1015 sets P₀ _(_)_(PUSCH), α, P_(SRS) _(_) _(OFFSET)(0) (first SRS power offset parameter(pSRS-Offset)) that is a power offset for the P-SRS, and P_(SRS) _(_)_(OFFSET)(1) (second SRS power offset parameter (pSRS-OffsetAp)) that isa power offset for the A-SRS, generates a signal including informationindicating the configuration, as a radio resource control signal, andnotifies each of the terminals 2 of the generated signal through thetransmission unit 107 on the PDSCH. Furthermore, the transmission powersetting unit 1015 sets a TPC command, generates information indicatingthe TPC command, and notifies each of the terminals 2 of the generatedinformation on the PDCCH through the transmission unit 107. Moreover, αmentioned here is a coefficient that, together with a path loss value,is used to set the transmission power, and by which to indicate theextent to which a path loss is compensated for, in other words, acoefficient (an attenuation coefficient or a path loss compensationcoefficient) by which to determine to what extent the transmission poweris increased or decreased according to the path loss (to be moreprecise, by which to determine to what extent the transmission power isadjusted). Normally, α is a value from 0 to 1. If α is 0, the adjustmentof the power in accordance with the pass loss is not made. If α is 1,the transmission power for the terminal 2 is increased or decreased insuch a manner that the path loss does not have an effect on the basestation 1. Furthermore, a TPC command for the SRS is set by taking intoconsideration a state of the terminal 2, information indicating the TPCcommand is generated, and the generated information is notified to eachof the terminals 2 through the transmission unit 107 on the PDCCH.Furthermore, a DCI format including the TPC command is generated and isnotified to each of the terminals 2 through the transmission unit 107 onthe PDCCH.

The control unit 103 generates a control signal for performing thecontrol of the reception unit 105 and of the transmission unit 107,based on the control information from the higher layer processing unit101. The control unit 103 outputs the generated control signal to thereception unit 105 and the transmission unit 107, and thus performs thecontrol of the reception unit 105 and of the transmission unit 107.

The reception unit 105 outputs to the higher layer processing unit 101information that is obtained by demultiplexing, demodulating, anddecoding a signal received from the terminal 2 through the transmit andreceive antenna 111 according to the control signal being input from thecontrol unit 103. The radio reception unit 1057 converts (down-converts)an uplink signal received through the transmit and receive antenna 111into an intermediate frequency (IF), removes an unnecessary frequencycomponent, controls an amplification level in such a manner as tosuitably maintain a signal level, performs orthogonal demodulation basedon an in-phase component and an orthogonal component of the receivedsignal, and converts the resulting orthogonally-demodulated analogsignal into a digital signal. The radio reception unit 1057 removes aportion corresponding to the guard interval (GI) from the digital signalthat results from the conversion. The radio reception unit 1057 performsFast Fourier Transform (FFT) on the signal from which the guard intervalis removed, and outputs the resulting signal to the demultiplexing unit1055 that extracts the signal in the frequency domain.

The demultiplexing unit 1055 demultiplexes the signal being input fromthe radio reception unit 1057 into signals such as the PUCCH, the PUSCH,the UL DMRS, and the SRS. Moreover, the demultiplexing is performedbased on allocation information on the radio resource, which isdetermined in advance by the base station 1 and is notified to eachterminal 2. Furthermore, the demultiplexing unit 1055 makes anadjustment of channels, the PUCCH and the PUSCH, from a channel estimatebeing input from the channel measurement unit 109. Furthermore, thedemultiplexing unit 1055 outputs the UL DMRS and the SRS, which resultfrom the demultiplexing, to the channel measurement unit 109.

The demodulation unit 1053 performs Inverse Discrete Fourier Transform(IDFT) on the PUSCH, acquires a modulation symbol, and performsmodulation of the received signal on each of the modulation symbols inthe PUCCH and the PUSCH, using a modulation scheme that is prescribed inadvance, such as Binary Phase Shift Keying (BPSK), Quadrature PhaseShift Keying (QPSK), 16 Quadrature Amplitude Modulation (16 QAM), or 64quadrature amplitude modulation (64 QAM), or that is notified by thebase station 1 to each of the terminals 2 with the downlink controlinformation.

The decoding unit 1051 performs decoding on the demodulated coded bitsin the PUCCH and the PUSCH at the coding rate in compliance with acoding scheme that is prescribed in advance, or is notified in advanceby the base station 1 to the terminal 2 with the uplink grant (ULgrant), and outputs the decoded data information and the uplink controlinformation to the higher layer processing unit 101.

The channel measurement unit 109 measures the channel estimate, thechannel quality, and the like from the UL DMRS being referred to as theuplink demodulation reference signal and the SRS, which are input fromthe demultiplexing unit 1055, and outputs a result of the measurement tothe demultiplexing unit 1055 and the higher layer processing unit 101.Furthermore, the channel measurement unit 109 measures received powerand/or reception quality of first to n-th signals, and outputs a resultof the measurement to the demultiplexing unit 1055 and the higher layerprocessing unit 101.

The transmission unit 107 generates the reference signal for downlink(downlink reference signal) in accordance with the control signal beinginput from the control unit 103, codes and modulates the datainformation being input from the higher layer processing unit 101 andthe downlink control information, and multiplexes the PDCCH, the PDSCH,and the downlink reference signal, and transmits a signal to theterminal 2 through the transmit and receive antenna 111.

The coding unit 1071 performs the coding, such as the turbo coding, theconvolutional coding, and the block coding, on the downlink controlinformation being input from the higher layer processing unit 101 andthe data information. The modulation unit 1073 performs modulation onthe coded bits with the modulation schemes such as QPSK, 16 QAM, and 64QAM. The downlink reference signal generation unit 1079 generates as thedownlink reference signal a sequence that is obtained according to arule that is prescribed in advance based on the cell ID for identifyingthe base station 1 and that is already known to the terminal 2 and thelike. The multiplexing unit 1075 multiplexes each modulated channel andthe generated downlink reference signal.

The radio transmission unit 1077 performs Inverse Fast Fourier Transform(IFFT) on the multiplexed modulation symbol, performs the modulation incompliance with an OFDM scheme, appends the guard interval to theOFDM-modulated OFDM symbol, generates a digital signal in a baseband,converts the digital signal in the baseband into an analog signal,generates an in-phase component and an orthogonal component in anintermediate frequency from the analog signal, removes frequencycomponents unnecessary for an intermediate frequency band, converts(up-converts) the signal in the intermediate frequency into ahigh-frequency signal, removes unnecessary frequency components, andperforms power amplification, and outputs a final result to the transmitand receive antenna 111 for transmission.

FIG. 2 is a schematic block diagram illustrating a configuration of theterminal 2 according to the present embodiment. As illustrated, theterminal 2 may be configured to include a higher layer processing unit201, a control unit 203, a reception unit 205, a transmission unit 207,a channel measurement unit 209, and a transmit and receive antenna 211.Furthermore, the higher layer processing unit 201 may be configured toinclude a radio resource control unit 2011, a measurement control unit2013, and a transmission power control unit 2015. Furthermore, thereception unit 205 may be configured to include a decoding unit 2051, ademodulation unit 2053, a demultiplexing unit 2055, and a radioreception unit 2057. Furthermore, the transmission unit 207 may beconfigured to include a coding unit 2071, a modulation unit 2073, amultiplexing unit 2075, and a radio transmission unit 2077.

The higher layer processing unit 201 outputs to a transmission unit theuplink data information that is generated by a user operation and thelike. Furthermore, the higher layer processing unit 201 performsprocessing of a medium access control layer, a packet data convergenceprotocol layer, a radio link control layer, and a radio resource controllayer.

The radio resource control unit 2011 that is included in the higherlayer processing unit 201 performs management of various pieces ofconfiguration information on the terminal 2 itself. Furthermore, theradio resource control unit 2011 generates information that is arrangedin each uplink channel and outputs the generated information to thetransmission unit 207. The radio resource control unit 2011 generatesthe control information for performing the control of the reception unit205 and of the transmission unit 207, based on various pieces ofconfiguration information on the terminal 2 itself, which is set withthe downlink control information that is notified from the base station1 on the PDCCH and with radio resource control information that isnotified on the PDSCH, and which is managed by the radio resourcecontrol unit 2011, and outputs the generated control information to thecontrol unit 203. Furthermore, the radio resource control unit 2011 setsvarious parameters of each signal, based on pieces of informationrelating to configurations of first to n-th signals, which are notifiedfrom the base station 1. The pieces of information being set aregenerated and output the transmission unit 207 through the control unit203.

The radio resource control unit 2011 that is included in the higherlayer processing unit 201 acquires from the reception unit 205information indicating a sounding subframe (an SRS subframe and an SRStransmission subframe) that is a subframe by which to reserve a radioresource for transmitting the SRS that is broadcast by the base station1, and a bandwidth of the radio resource that is reserved to transmitthe SRS within the sounding subframe, information indicating a subframeby which to transmit a periodic SRS that is notified by the base station1 to the terminal 2 itself, a frequency band, and an amount of cyclicshift that is used in a CAZAC sequence for the periodic SRS, andinformation indicating the frequency band in which to transmit anaperiodic SRS that is notified by the base station 1 to the terminal 2itself, and the amount of cyclic shift that is used in a CAZAC sequencefor the aperiodic SRS.

The radio resource control unit 2011 performs control of SRStransmission in accordance with the information described above.Specifically, the radio resource control unit 2011 controls thetransmission unit 207 in such a manner that the periodic SRS istransmitted one time or periodically in accordance with the informationrelating to the periodic SRS described above. Furthermore, in a casewhere an SRS request (SRS indicator) being input from the reception unit205 makes a request for transmission of the aperiodic SRS, the radioresource control unit 2011 transmits the aperiodic SRS only the numberof times (for example, one time) that is prescribed in advance, inaccordance with information relating to the aperiodic SRS.

The transmission power control unit 2015 that is included in the higherlayer processing unit 201 performs transmission power control based onconfigurations of the transmission power of each of the PUCCH, thePUSCH, the periodic SRS, and the aperiodic SRS, and thus outputs thecontrol information to the control unit 203. Specifically, thetransmission power control unit 2015 controls each of the transmissionpower for the periodic SRS and the transmission power for the aperiodicSRS, based on P₀ _(_) _(PUSCH), α, P_(SRS) _(_) _(OFFSET)(0) (first SRSpower offset (pSRS-Offset)) that is a power offset for the periodic SRS,P_(SRS) _(_) _(OFFSET)(1) (second SRS power offset (pSRS-OffsetAp)) thatis a power offset for the aperiodic SRS, and the TPC command, which areacquired from the reception unit 205. Moreover, the transmission powercontrol unit 2015 causes P_(SRS) _(_) _(OFFSET) to switch between afirst power offset and a second power offset according to whether theSRS is the periodic SRS or the aperiodic SRS.

The measurement control unit 2013 that is included in the higher layerprocessing unit 201 instructs the reception unit 205, the channelmeasurement unit 209, and the transmission unit 207 to perform receivedpower measurement, received quality measurement, channel estimation, orthe like, through the control unit 203, based on information relating toa measurement configuration, which is notified from the base station 1,information relating to the measurement object configuration,information relating to the reporting configuration, informationrelating to the measurement reporting configuration, and informationrelating to the CQI reporting configuration.

The control unit 203 generates a control signal for performing thecontrol of the reception unit 205 and of the transmission unit 207,based on the control information from the higher layer processing unit201. The control unit 203 outputs the generated control signal to thereception unit 205 and the transmission unit 207, and thus performs thecontrol of the reception unit 205 and of the transmission unit 207.

In accordance with the control signal being input from the control unit203, the reception unit 205 demultiplexes, demodulates, and decodes areceived signal that is received from the base station 1 through thetransmit and receive antenna 211, and outputs the resulting informationto the higher layer processing unit 201.

The radio reception unit 2057 converts (down-converts) an uplink signalreceived through each received antenna into an intermediate frequency,removes an unnecessary frequency component, controls an amplificationlevel in such a manner as to suitably maintain a signal level, performsorthogonal demodulation based on an in-phase component and an orthogonalcomponent of the received signal, and converts the resultingorthogonally-demodulated analog signal into a digital signal. The radioreception unit 2057 removes a portion equivalent to the guard intervalfrom the digital signal that results from the conversion, performs FastFourier Transform on the signal from which the guard interval isremoved, and extracts a signal in the frequency domain.

The demultiplexing unit 2055 demultiplexes the extracted signal into thephysical downlink control channel (PDCCH), the PDSCH, and the downlinkreference signal (DRS). Moreover, the demultiplexing is performed basedon the allocation information on the radio resource and the like thatare notified with the downlink control information.

Furthermore, the demultiplexing unit 2055 makes an adjustment ofchannels, the PDCCH and the PDSCH, from a channel estimate being inputfrom the channel measurement unit 209. Furthermore, the demultiplexingunit 2055 outputs the downlink reference signal, which results from thedemultiplexing to the channel measurement unit 209.

The demodulation unit 2053 performs demodulation for the PDCCH incompliance with the QPSK modulation scheme and outputs a result of thedemodulation to the decoding unit 2051. The decoding unit 2051 attemptsthe decoding of the PDCCH and, in a case where the decoding succeeds,outputs the decoded downlink control information to the higher layerprocessing unit 201.

The demodulation unit 2053 performs the demodulation, which is incompliance with the modulation scheme that is notified with the downlinkcontrol information, such as QPSK, 16 QAM, and 64 QAM, for the PDSCH,and outputs a result of the demodulation to the decoding unit 2051. Thedecoding unit 2051 performs the decoding on the coding rate that isnotified with the downlink control information, and outputs the decodeddata information to the higher layer processing unit 201.

The channel measurement unit 209 measures a downlink path loss from thedownlink reference signal being input from the demultiplexing unit 2055,and outputs the measured path loss to the higher layer processing unit201.

Furthermore, the channel measurement unit 209 calculates a downlinkchannel estimate from the downlink reference signal and outputs thecalculated downlink channel estimate to the demultiplexing unit 2055.

Furthermore, the channel measurement unit 209 performs the receivedpower measurement or the received quality measurement of the firstsignal and/or the second signal in accordance with various pieces ofinformation relating to the measurement configuration, which is notifiedfrom the measurement control unit 2013 through the control unit 203. Aresult of the measurement is output to the higher layer processing unit201.

Furthermore, in a case where the channel measurement unit 209 isinstructed to perform the channel estimation of the first signal and/orthe second signal, it may output a result of the channel estimation ofeach signal to the higher layer processing unit 201.

In accordance with the control signal being input from the control unit203, the transmission unit 207 generates the UL DMRS and/or the SRS,codes and modulates the data information being input from the higherlayer processing unit 201, multiplexes the PUCCH, the PUSCH, the UL DMRSand/or the SRS that are generated, adjusts the transmission power of thePUCCH, the PUSCH, the UL DMRS and the SRS, and transmits a result of themultiplexing to the base station 1 through the transmit and receiveantenna 211 with the adjusted transmission power.

Furthermore, in a case where information relating to a result of themeasurement is output from the higher layer processing unit 201, thetransmission unit 207 transmits to the base station 1 the informationbeing output through the transmit and receive antenna 211.

Furthermore, in a case where channel state information that is theresult of the channel estimation is output from the higher layerprocessing unit 201, the transmission unit 207 feeds the channel stateinformation back to the base station 1. To be more precise, the higherlayer processing unit 201 generates the channel state information (CSI)based on the result of the measurement, which is notified from thechannel measurement unit, and feeds the generated channel stateinformation back to the base station 1 through the control unit 203.

The coding unit 2071 performs the coding, such as the turbo coding, theconvolutional coding, and the block coding, on the uplink controlinformation being input from the higher layer processing unit 201 andthe data information. The modulation unit 2073 modulates the coded bitsbeing input from the coding unit 2071 with the modulation scheme such asBPSK, QPSK, 16 QAM, or 64 QAM.

An uplink reference signal generation unit 2079 generates the CAZACsequence that is obtained according to the rule which is prescribed inadvance based on the cell ID for identifying the base station 1, thebandwidth in which the UL DMRS and the SRS are arranged, and the like,and that is already known to the base station 1. Furthermore, inaccordance with the control signal being input from the control unit203, the uplink reference signal generation unit 2079 gives the cyclicshift to the CAZAC sequences for the generated UL DMRS and SRS.

In accordance with the control signal being input from the control unit203, the multiplexing unit 2075 rearranges PUSCH modulation symbols inparallel and then performs Discrete Fourier Transform (DFT) on thearranged PUSCH modulation symbols, and multiplexes PUCCH and PUSCHsignals and the generated UL DMRS and SRS.

The radio transmission unit 2077 performs Inverse Fast Fourier Transform(IFFT) on the multiplexed signal, performs the modulation in compliancewith an SC-FDMA scheme, appends the guard interval to theSC-FDMA-modulated SC-FDMA symbol, generates a digital signal in abaseband, converts the digital signal in the baseband into an analogsignal, generates an in-phase component and an orthogonal component inan intermediate frequency from the analog signal, removes frequencycomponents unnecessary for an intermediate frequency band, converts(up-converts) the signal in the intermediate frequency into ahigh-frequency signal (radio frequency), removes unnecessary frequencycomponents, performs power amplification, and outputs a final result tothe transmit and receive antenna 211 for transmission.

According to the first embodiment, the base station 1 transmits to theterminal 2 information for indicating a signal that is used in thereceived power measurement. Based on the information for indicating thesignal that is used in the received power measurement and is transmittedfrom the base station 1, the terminal 2 measures the received power ofthe signal. To be more precise, in a case where the base station 1 givesan instruction to perform the received power measurement based on thefirst signal, the terminal 2 performs the received power measurementbased on the first signal.

Furthermore, in a case where the base station 1 gives an instruction toperform the received power measurement based on the second signal, theterminal 2 performs the received power measurement based on the secondsignal.

Furthermore, in a case where the base station 1 gives an instruction toperform the received power measurement based on an n-th (n is a naturalnumber) signal, the terminal 2 performs the received power measurementbased on the n-th signal. Here, the first signal and the second signalmay be individually set in terms of at least one among a transmissionperiod, a measurement period, resource allocation, scrambling initiationID, the number of antenna ports, and transmission power control. Forexample, the transmission period of the second signal may possibly belonger (be set to be longer) than that of the first signal.

Parameters may not be set for each of the first signal and the secondsignal, among the transmission period, the measurement period, theresource allocation, the scrambling initiation ID, transmissionbandwidth, the number of antenna ports, and the transmission powercontrol. For example, information relating to the measurement period orinformation relating to number of antenna ports may be set as theinformation relating to a configuration of the first signal, andinformation relating to the resource allocation, information relating tothe transmission period, information relating to the number of antennaports, or information relating to the scrambling initiation ID may beset to be in the second signal. Moreover, in some cases, the scramblinginitiation ID is also referred to as a virtual cell ID or a virtual ID.The measurement period is a period with which a signal is received andis measured. Furthermore, in some cases, the measurement period is alsoreferred to as a measurement subframe pattern (measSubframePattern).

Furthermore, the measurement subframe pattern may be indicated by a bitmap. Furthermore, the measurement subframe pattern may be indicated by aperiod or a subframe offset.

The terminal 2 may not periodically perform the received powermeasurement. To be more precise, the terminal 2 may perform the receivedpower measurement based on specific information.

The terminal 2 performs the received power measurement in the subframethat is indicated by the measurement subframe pattern. In a case where,in TDD, the subframe indicated by the measurement subframe pattern is anuplink subframe, the received power measurement may not be performed inthe indicated subframe.

In a case where the subframe indicated by the measurement subframepattern is a flexible subframe and is used as the uplink subframe, theterminal 2 may not perform the received power measurement with theindicated subframe.

Furthermore, that does not even need to be reflected as a result of themeasurement. For example, the transmission period or the measurementperiod may be independently set for the first signal and the secondsignal.

Furthermore, the transmission period of the second signal may not beperiodic. For example, the transmission period may be indicated by thebit map.

Furthermore, transmission of the second signal may be associated with aspecific physical channel/physical signal.

Furthermore, the transmission of the second signal may be indicated bythe downlink control information. Furthermore, the transmission of thesecond signal may be associated with specific information.

Furthermore, the resource allocation may be independently set for thefirst signal and the second signal.

Furthermore, the scrambling initiation ID may independently set for thefirst signal and the second signal. A sequence generation method may beset for the first signal and the second signal. Moreover, in some cases,the sequence is also referred to as a signal sequence, a referencesignal sequence, or a channel sequence. For each of the first signal andthe second signal, the sequence may be initialized with an independentscheme. To be more precise, c_(init), a parameter that independentlyindicates an initial value of the sequence may be defined with the firstsignal and the second signal.

The parameter indicating the initial value of the sequence may be setbased on a physical cell ID.

Furthermore, the parameter indicating the initial value of the sequencemay be set based on the virtual cell ID.

Furthermore, the first signal and the second signal are the same in theresource allocation, but may be different in the transmission periodfrom each other. For example, while the first signal is transmitted withevery subframe, the second signal may be transmitted with a specificperiod. Information relating to the transmission period of the secondsignal at this time may be notified by a higher layer and may be set.

Furthermore, the first signal and the second signal may be different inthe transmission bandwidth from each other. For example, the firstsignal is transmitted at all times with the resource being mapped ontoan entire system bandwidth, but the second signal may be transmittedwith the resource being mapped onto a specific transmission bandwidth.Information relating to the transmission bandwidth of the second signalat this time may be notified by a higher layer and may be set.

Furthermore, at this time, the signal sequences of the first signal andthe second signal may be initialized with different cell IDs. Forexample, the signal sequence of the first signal may be initializedbased on a physical cell ID or a virtual cell ID.

The signal sequence of the second signal may be initialized based on avirtual cell ID. Moreover, a third signal also may be handled in thesame manner. To be more precise, various parameters may be independentlyset for the first to third signals. Moreover, an n-th signal (n is anatural number) also may be handled in the same manner. To be moreprecise, various parameters may be independently set to be in theinformation relating to the first to n-th signals.

Furthermore, various parameters that are set to be in pieces ofinformation relating to configurations of the first to n-th signals maynot be necessarily the same parameter. To be more precise, variousparameters that are set to be in pieces of information relating to theconfigurations of the first to n-th signals may be independently set.These parameters may be set by the higher layer signaling (radioresource control signaling, dedicated signaling, or an RRC message).

Furthermore, these parameters may be set using the PDCCH. That is, theseparameters may be set using the higher layer signaling and/or the PDCCH.Furthermore, the physical cell ID is a parameter that is set to bespecific to a cell, and the virtual cell ID is a parameter that is setto be specific to a terminal. To be more precise, the terminals 2 withinthe cell share the same value of the physical cell ID, but the virtualcell ID is independently set to be in the terminals 2. For example, theterminal 2 may detect the physical cell ID using the synchronizationsignal(s). Furthermore, the terminal 2 may acquire the virtual cell IDbased on information that is transmitted using a higher layer signaland/or the PDCCH.

The first to n-th signals may be transmitted with independent antennaports, respectively. In the first to n-th signals, in a case wheremultiple antenna ports are set, the antenna ports in accordance with thenumber of antenna ports may be set.

Among the first to n-th signals, in the signal for which the multipleantenna ports are set, the resources may be allocated in such a mannerthat the resources do not overlap between the antenna ports.Furthermore, among the first to n-th signals, in the signal for whichthe multiple antenna ports are set, the antenna ports may be differentin weighting from one another. Among the first to n-th signals, in thesignals for which the multiple antenna ports are set, control may beperformed in such a manner that the antenna ports are different incyclic shift from one another.

The pseudo-random sequences for the first to n-th signals may begenerated based on the physical cell ID (PCI: Physical layer CellIdentity, Physical Cell Identifier).

Furthermore, the pseudo-random sequences for the first to n-th signalsmay be generated based on the virtual cell identify (VCID).

Furthermore, the pseudo-random sequences for the first to n-th signalsmay be generated based on the scrambling initiation ID (Identity). Ineach signal, in a case where the virtual cell ID or the scramblinginitiation ID is not set (for example, in a case where an effectivevirtual cell ID or scrambling initiation ID is not set by a higherlayer), the pseudo-random sequence may be generated based on thephysical cell ID.

Methods of generating the pseudo-random sequences for the first to n-thsignals may be individually defined.

Furthermore, initialization of each of the pseudo-random sequences forthe first to n-th signals may be defined in an independent way. To bemore precise, each of the pseudo-random sequences for the first to n-thsignals may be initialized in an independent way.

Furthermore, a base sequence may be generated based on the pseudo-randomsequence.

Furthermore, a signal sequence may be generated based on thepseudo-random sequence.

Furthermore, the signal sequence may be generated based on the basesequence.

Furthermore, the pseudo-random sequence may be used as a scramblingsequence.

Furthermore, the signal sequence may be generated based on theZadoff-Chu sequence.

Furthermore, the signal sequence may be generated based on a Goldsequence.

By allocating an independent signal sequence to each of the first signaland the second signal, the terminal 2 can improve detection accuracy ofeach of the first signal and the second signal.

By allocating an independent signal sequence to each of the first signaland the second signal, the terminal 2 can determine whether or not asignal is transmitted from the cell in which the terminal 2 itself isregistered.

Furthermore, in a case where the first signal and the second signal arethe same in the resource allocation, the terminal 2 can detect the firstsignal and/or second signal by a difference in the signal sequencebetween the first signal and the second signal. To be more precise, theterminal 2 can identify each signal by the difference in the signalsequence.

Furthermore, a frequency shift may be applied to the resource allocation(mapping to resource elements or mapping to physical resources) to eachof the first to n-th signals. Furthermore, the frequency shift may beset based on the physical cell ID. Furthermore, the frequency shift maybe set based on the virtual cell ID.

Information relating to the resource allocation to each of the first ton-th signals may be notified by the higher layer signaling. In somecases, the information relating to the resource allocation is alsoreferred to as information relating to a configuration of the radioresource.

Pieces of information relating to the configurations of the first ton-th signals may be notified by the higher layer signaling from the basestation 1 to the terminal 2. Furthermore, among the pieces ofinformation relating to the configurations of the first to n-th signals,pieces of information relating to multiple settings with respect to oneterminal 2 may be set to be in any one of the signals.

The first to n-th signals may be referred to as first to n-th referencesignals, respectively.

Furthermore, among the first to n-th signals, at least one signal may beused in the demodulation of a physical broadcast channel.

Furthermore, among the first to n-th signals, at least one signal may beused in the demodulation of the physical downlink control channel.

Furthermore, among the first to n-th signals, at least one signal may beused in the demodulation of the physical downlink shared channel.

Furthermore, among the first to n-th signals, at least one signal may beused in the demodulation of a physical multicast channel (PMCH).

Furthermore, among the first to n-th signals, at least one signal may beused in time/frequency synchronization detection.

Furthermore, among the first to n-th signals, at least one signal may beused in the channel estimation. To be more precise, at least one signalmay be used in the feedback on the channel state information (CSI).

Furthermore, among the first to n-th signals, at least one signal may beused in the received quality measurement.

Furthermore, among the first to n-th signals, at least one signal may beused in the received power measurement.

Furthermore, among the first to n-th signals, at least one signal may beused in mobility management.

Furthermore, among the first to n-th signals, at least one signal may beused in resource management.

Furthermore, among the first to n-th signals, at least one signal may beused in positioning detection.

The first to n-th signals may be different in the number of resourceelements that are arranged within one physical resource block (PRB) orone pair of PRBs. For example, within one subframe (or one slot), thenumber of resource elements that are used in the transmission of thesecond signal may possibly be (be set to be greater) greater than thenumber of resource elements that are used in the transmission of thefirst signal.

Moreover, in a case where the base station 1 instructs the terminal 2 tomeasure the received power based on the second signal, the terminal 2may calculate a downlink path loss based on the result of themeasurement, and may use the calculated downlink path loss in control ofuplink transmission power.

Here, in some cases, the received power measurement is also referred toas reference signal received power (RSRP) measurement or received signalpower measurement. Furthermore, in some cases, the received qualitymeasurement is also referred to as reference signal received quality(RSRQ) measurement or received signal quality measurement.

Furthermore, the resource allocation (mapping to resource elements ormapping to physical resources) to the second signal may befrequency-shifted. The frequency shift of the second signal may bedetermined based on the physical cell ID. Furthermore, the frequencyshift of the second signal may be determined based on the virtual cellID.

As one example, the base station 1 notifies the terminal 2 ofinformation indicating whether or not the received power measurement ofthe second signal is performed. In a case where the instructioninformation indicates that the received power measurement of the secondsignal can be performed, the terminal 2 performs the received powermeasurement of the second signal. At this time, the terminal 2 mayperform the received power measurement of the first signal in parallelwith the second signal. In a case where the instruction informationindicates that the received power measurement cannot be performed, theterminal 2 performs only the received power measurement of the firstsignal. Moreover, information indicating whether or not the receivedquality measurement of the second signal is performed may be included inthe instruction information. Furthermore, the received power measurementof the third signal may be performed without the instructioninformation.

Furthermore, as another example, the base station 1 notifies theterminal 2 of the information indicating whether or not the receivedpower measurement of the first signal or the received power measurementof the second signal is performed. In a case where the instructioninformation indicates that the received power measurement of the firstsignal is performed, the terminal 2 performs the received powermeasurement of the first signal. In a case where the instructioninformation indicates that the received power measurement of the secondsignal is performed, the terminal 2 performs the received powermeasurement of the second signal. To be more precise, the instructioninformation is information indicating switching of the received powermeasurement. Furthermore, the information indicating whether or not thereceived quality measurement is performed may be included in theinstruction information. Furthermore, the received power measurement ofthe third signal may be performed without the instruction information.

As illustrated in FIG. 3, the terminal 2 identifies a condition, andperforms the received power measurement based on the condition. Theterminal 2 identifies the condition (Step S301). In the case ofcondition A (S301: condition A), the terminal 2 performs the receivedpower measurement based on the first signal (Step S302). Furthermore, inthe case of condition B (S301: condition B), the terminal 2 performs thereceived power measurement based on the second signal (Step S303).Furthermore, in the case of the condition B, the terminal 2 may performthe received power measurement based on the first signal. Furthermore,in the case of the condition B, the terminal 2 may perform the receivedpower measurement based on an n-th signal.

Here, referring to FIG. 3, according to the first embodiment, theinstruction information that does not indicate that the received powermeasurement is performed based on the second signal is described asbeing included in the condition A. Furthermore, the instructioninformation indicating that the received power measurement is performedbased on the second signal is included in the condition B. At this time,in a case where information relating to a configuration of the thirdsignal is set to be in the terminal 2, the terminal 2 may perform thereceived power measurement based on the third signal regardless of thecondition A or the condition B.

With the instruction information that is notified from the base station1, it can be determined whether the received power of the first signalor the received power of the second signal is measured. Moreover, in acase where the base station 1 does not transmit the first signal,because the terminal 2 perform control in such a manner that the firstsignal is not monitored, power consumption can be correspondinglysuppressed.

(Second Embodiment)

Next, a second embodiment of the present invention is described.According to the second embodiment, the base station 1 transmits to theterminal 2 information relating to a configuration of at least onesignal among the information relating to the configuration of the firstsignal and the information relating to the configuration of the secondsignal. In a case where the information relating to the configuration ofat least one signal is detected among the information relating to theconfiguration of the first signal and the information relating to theconfiguration of the second signal, the terminal 2 performs the receivedpower measurement on the detected signal. The first signal and thesecond signal are different from each other in terms of the conditionfor performing the received power measurement. For example, the receivedpower of the first signal may be measured regardless of the presence orabsence of the configuration of the first signal. To be more precise,the terminal 2 may possibly measure the received power of the firstsignal by default. To be more precise, the first signal is defined as asignal that is determined in a manner that is particular to a system,and the terminal 2 may perform the received power measurement based onthis signal.

Furthermore, the received power of the second signal may possibly bemeasured only in a case where the information relating to theconfiguration of the second signal is set to be in the terminal 2.

Furthermore, if the pieces of information relating to the configurationsof multiple second signals are not set to be in the terminal 2, thereceived power of the second signals may not be measured. To be moreprecise, in a case where one piece of configuration information relatingto the configuration of the second signal is present, the received powerof the second signal may not be measured.

Furthermore, in a case where only one piece of information relating tothe configuration of the second signal is set to be in the terminal 2,the terminal 2 may perform the channel estimation based on the secondsignal.

Furthermore, in a case where the information relating to theconfiguration of the second signal is set to be in the terminal 2, thereceived power measurement may be performed on the second signal insteadof on the first signal.

Furthermore, the information relating to the configuration of the firstsignal may be determined in a manner that is particular to the system.The information relating to the configuration of the first signal may benotified as the broadcast information or the system information. Theinformation relating to the configuration of the first signal may beindividually notified from the base station 1 to the terminal 2.

Furthermore, the information relating to the configuration of the secondsignal may be notified with the broadcast information or the systeminformation. The information relating to the configuration of the secondsignal may be individually notified from the base station 1 to theterminal 2.

Information indicating the transmission bandwidth may be included in theinformation relating to the configuration of the second signal.

Furthermore, information indicating the virtual cell ID (scramblinginitiation ID) for generating the signal sequence for the second signalmay be included in the information relating to the configuration of thesecond signal.

Furthermore, information indicating the transmission period and thesubframe offset may be included in the information relating to theconfiguration of the second signal.

Furthermore, information indicating the resource allocation may beincluded in the information relating to the configuration of the secondsignal.

Furthermore, information indicating the number of antenna ports may beincluded in information relating to the configuration of the secondsignal.

Furthermore, information for determining the transmission power of thesecond signal may be included in the information relating to theconfiguration of the second signal. For example, the information fordetermining the transmission power of the second signal may be a poweroffset.

Furthermore, the information for determining the transmission power ofthe second signal may be a transmission power value of the secondsignal.

Furthermore, for the second signal, the frequency shift may bedetermined with a value that is set to be in the virtual cell ID.

Furthermore, for the second signal, the frequency shift may bedetermined with a value that is set to be in the physical cell ID.

Furthermore, the resource allocation to the second signal may bearranged in such a manner as to avoid the resource allocation to thefirst signal. That is, the first signal may be arranged in the resourcethat is not used among the resources (possibly the resource element)that are to be used for the transmission of the second signal.

Furthermore, the second signal may be arranged in the resource that isnot used among the resources that are to be used for the transmission ofthe first signal.

Furthermore, the resource allocation to the second signal may overlapthe resource allocation to the first signal.

Furthermore, the resource allocation to the second signal may overlapthe resource allocation to the demodulation reference signal.

The resource allocation to the second signal may overlap the resourceallocation to the channel state information reference signal.

Furthermore, the resource allocation to the second signal may overlapthe resource allocation to the cell-specific reference signal.

Furthermore, the resource allocation to the second signal may overlapthe resource allocation to a positioning reference signal (P-RS).

Furthermore, the second signal may be a signal for the received powermeasurement.

Furthermore, the second signal may be a signal for the channelestimation. To be more precise, various parameters for setting thesecond signal may be set to be in the information relating to theconfiguration of the second signal.

Furthermore, in a case where the information relating to theconfiguration of the second signal is linked to specific information,the received power measurement may be performed based on the secondsignal. For example, in a case where the information relating to theconfiguration of the second signal is linked to information relating tothe measurement object configuration, the received power measurement maybe performed based on the second signal.

Furthermore, in a case where the pieces of information relating to theconfigurations of multiple second signals are set to be in the terminal2, if among the pieces of information relating to the configurations,pieces of information relating to the virtual cell IDs are set to bedifferent from one another, the received power measurement is performedindividually and independently. If, among the pieces of informationrelating to the configurations, pieces of information relating to thevirtual cell IDs are the same value, the received power measurement maybe performed for the shared signal. This may be applied to an n-thsignal (n is a natural number).

For example, in a case where the resource allocation to the first signaland the resource allocation to the second signal overlap each other, foreach of the first signal and the second signal, the signal sequence maybe initialized in an independent scheme (method). Furthermore, in a casewhere the radio resource allocated to the first signal and the radioresource allocated to the second signal overlap each other, for each ofthe first signal and the second signal, the signal sequence may beinitialized in an independent way. Furthermore, for the second signal,the signal sequence may be initialized with the virtual cell ID. To bemore precise, the signal sequence for the first signal may be generatedbased on the physical cell ID or the virtual cell ID. The signalsequence for the second signal may be generated based on the virtualcell ID.

Furthermore, in the case where the resource allocation to the firstsignal and the resource allocation to the second signal overlap eachother, a value of the cell ID (the physical cell ID or the virtual cellID) that is used in the signal sequence for each signal may be appliedto the frequency shift.

Furthermore, in the case where the resource allocation to the firstsignal and the resource allocation to the second signal overlap eachother, the signals may be transmitted from different antenna ports,respectively. To be more precise, for the first signal and the secondsignal, the signal sequence may possibly be independently generated by adifference between the antenna ports.

Here, referring to FIG. 3, according to the second embodiment, thecondition A may include a condition that the terminal 2 is notconfigured with the information relating to the configuration of thesecond signal. That is, the condition A may include a condition that theterminal 2 is configured with only the information relating to theconfiguration of the first signal. The condition B may include acondition that the terminal 2 is configured with the informationrelating to the configuration of the second signal.

The terminal 2 can determine whether or not the received power of thesecond signal can be measured, according to whether or not theinformation relating to the configuration of the second signal isconfigured. To be more precise, because the information indicatingwhether or not the second signal is measured for the terminal 2 isunnecessary, the base station 1 does not need to additionally transmitto the terminal 2 an amount of information indicating whether or not thesecond signal is measured.

(Third Embodiment)

Next, a third embodiment is described. According to the thirdembodiment, the base station 1 transmits to the terminal 2 informationrelating to a carrier type (component carrier corresponding to a cell)with respect to a certain cell. In a case where a first carrier type isindicated (set) with the information relating to the carrier type, theterminal 2 measures the received power for the cell on the basis of thefirst signal. In a case where a second carrier type is indicated withthe information relating to the carrier type, the terminal 2 measuresthe received power for the cell on the basis of the second signal. Atthis time, the base station 1 transmits the information relating to theconfiguration of the second signal to the terminal 2. Furthermore, thebase station 1 transmits the information relating to a measurementreport event with respect to the second signal to the terminal 2. Whenthe second carrier type is set for a certain cell, with a higher layer,the measurement report event with respect to the second signal is setfor the terminal 2. Furthermore, when the second carrier type is set fora certain cell, the terminal 2 measures the received power (RSRP) basedon the second signal. Furthermore, when the second carrier type is setfor a certain cell, the terminal 2 performs a measurement report basedon the measurement report event with the second signal. Here, in somecases, the carrier type is also referred to as a cell type.

Furthermore, the carrier type may indicate a type (a kind or a format)of component carrier corresponding to the cell.

Furthermore, the first carrier type may be set for the component carriercorresponding to the primary cell.

Furthermore, the first carrier type may be set for the component carriercorresponding to the secondary cell.

Furthermore, the first carrier type may be set for the component carriercorresponding to the serving cell.

Furthermore, the second carrier type may have a different definitionfrom the first carrier type.

Furthermore, the first carrier type or the second carrier type maypossibly be set for the serving cell.

Furthermore, the first carrier type or the second carrier type maypossibly be set for the primary cell.

Furthermore, the first carrier type or the second carrier type maypossibly be set for the secondary cell.

Furthermore, in the cell for which the second carrier type is set, insome cases, a part of the physical channels may be not transmitted thatis transmitted in the cell for which the first carrier type is set. Inthe cell for which the second carrier type is set, the base station 1may not transmit the cell-specific reference signal.

Furthermore, in the cell for which the second carrier type is set, thebase station 1 may not transmit the primary synchronization signal andthe secondary synchronization signal. To be more precise, in the cellfor which the first carrier type is set and in the cell for which thesecond carrier type is set, the same type of signal or the same type ofphysical channel may not necessarily be transmitted.

Furthermore, in the cell for which the second carrier type is set, thebase station 1 may not transmit the physical downlink control channel.

Furthermore, in the cell for which the second carrier type is set, theterminal 2 may not detect the signal or the physical channel that isscheduled with the physical cell ID.

In the cell for which the second carrier type is set, the time/frequencysynchronization may be performed with the second signal. In the cell forwhich the second carrier type is set, cell detection may be performedwith the second signal.

Furthermore, the second carrier type may be applied to a specific typeof cell. For example, the second carrier type may be applied to a smallcell or a femto cell and a phantom cell. The second carrier type may beapplied to only a specific terminal 2. That is, the first carrier typeand the second carrier type may be identified based on the configurationby the base station 1. The base station 1 may transmit the configurationwith respect to the physical channel/signal described above, as aconfiguration corresponding to the first carrier type.

Furthermore, the base station 1 may not transmit the configuration withrespect to the physical channel/physical signal described above, as aconfiguration corresponding to the second carrier type. That is, thebase station 1 may indicate the second carrier type by not transmittingthe configuration corresponding to the first carrier type.

The base station 1 may broadcasts information relating to the secondcarrier type. Furthermore, the base station 1 may broadcast theinformation relating to the second carrier type to the entire cell in astate of being included in the system information. The informationrelating to the second carrier type may possibly be detected by onlysome terminals. Furthermore, by the higher layer signaling, the basestation 1 may transmit the information relating to the second carriertype to each individual terminal. Furthermore, the information relatingto the second carrier type may be associated with specific information.To be more precise, even though the information relating to the secondcarrier type is not detected, if only specific information is detected,the terminal 2 may recognize the second carrier type as being set.

In the cell for which the second carrier type is set, in a case wherethe configuration of the second signal is not set, the terminal 2 maymeasure the received power based on the first signal. Furthermore, in acase where the configuration of the second signal is set, the terminal 2may measure the received power based on the second signal. At this time,the terminal 2 may not measure the received power based on the firstsignal.

Furthermore, the terminal 2 may set the path loss based on the receivedpower obtained from the second signal. Moreover, the terminal 2 may setthe transmission power of the uplink signal from the path loss.

Furthermore, with regard to the third signal, the terminal 2 may performthe received power measurement with respect to the cell regardless ofthe carrier type.

In the communication system in which a handover to a cell for which thesecond carrier type is set is possible, in a case where an instructionto perform the handover to the cell for which the second carrier type isset is given, the terminal 2 may perform the received power measurementbased on the second signal. Furthermore, in the communication system, aprocedure for the handover to the cell for which the second carrier typeis set may be performed.

In the communication system in which the handover to the cell for whichthe second carrier type is set is possible, in a case where the terminalgoes through (detects, experiences, or recognizes) a radio link failure(RLF) in the cell, the terminal may perform a reestablishment procedure.Furthermore, in the communication system in which the cell that is setto the second carrier type functions in a stand-alone manner, in thecase where the terminal goes through (detects, experiences, orrecognizes) the radio link failure (RLF) in the cell, the terminal mayperform the reestablishment procedure. Furthermore, at this time, theterminal 2 may perform the reestablishment procedure on the cell that isnot set to the second carrier type. Furthermore, in the communicationsystem in which the cell that is set to the second carrier typefunctions in a stand-alone manner, in the case where the terminal goesthrough (detects, experiences, or recognizes) the radio link failure(RLF) in the cell, the terminal may perform the reestablishmentprocedure. Moreover, in most cases, the reestablishment is also referredto as an RRC connection reestablishment.

Furthermore, in the communication system in which the cell that is setto the second carrier type functions in a stand-alone manner, in a casewhere information relating to the second carrier type is broadcast in astate of being set to be in the system information, the terminal 2 mayperform synchronization detection based on the second signal.Furthermore, at this time, the terminal 2 may perform the received powermeasurement based on the second signal. Furthermore, in a case where theinformation relating to the second carrier type is not set to be in thesystem information, the terminal 2 may perform the synchronizationdetection based on the primary synchronization signal or the secondarysynchronization signal. Furthermore, the terminal 2 may perform thereceived power measurement based on the first signal.

Furthermore, in the communication system in which the cell that is setto the second carrier type functions in a stand-alone manner, in a casewhere the information relating to the second carrier type is broadcastin a state of being included in the system information, with randomaccess, the terminal 2 may perform an initial connection to the cell. Tobe more precise, the terminal 2 may perform the random access to thecell for which the second carrier type is set. Furthermore, the terminal2 may detect a random access problem in the cell. When the random accessproblem is detected, the terminal 2 may notify a higher layer of therandom access problem, and the higher layer that is notified of therandom access problem may determine that radio link failure occurs. Atthat time, the reestablishment procedure may be triggered.

Furthermore, in the communication system in which the cell that is setto the second carrier type functions in a stand-alone manner, theterminal 2 may transmit a control channel corresponding to the physicaluplink control channel to the base station 1. However, the resourceallocation to the control channel may not be arranged in the same manneras with the physical uplink control channel.

Furthermore, in a case where, by a higher layer, an instruction toperform the reestablishment with respect to the cell that is set to thesecond carrier type is given by the base station 1, the terminal 2 mayperform the received power measurement based on the second signal.Furthermore, in a case where, by a higher layer, an instruction toperform the reestablishment with respect to the cell that is set to thesecond carrier type is not given by the base station 1, the receivedpower measurement may be performed based on the first signal.

In a case where the information relating to the configuration of thesecond signal is included in the received RRC message, the terminal 2may perform the received power measurement based on the second signal.The RRC message may be a message that is used to perform the handover.Furthermore, the RRC message may be a message that is used to indicate acell addition/removal. Furthermore, the RRC message may be a messageindicating measurement. The RRC message is notified with dedicatedsignaling.

One example of operation of each of the base station 1 and the terminal2 will be described below. For example, in the cell (for example, amacro cell) for which the first carrier type is set, the terminal 2performs the received power measurement based on at least the firstsignal. Here, the first signal is generated (or mapped) based on thephysical cell ID (for example, a value of the physical cell ID withrespect to the cell for which the first carrier type is set).Furthermore, the first signal is generated (or mapped) based on thevirtual cell ID (for example, a value of the virtual cell ID withrespect to the cell for which the first carrier type is set) that is setusing a higher layer signal (for example, a dedicated signal).

Here, the base station 1 transmits a parameter relating to the secondsignal to the terminal 2 in a state of being included in the higherlayer signal (for example, the dedicated signal). Here, any one ofinformation indicating a transmission period of the second signal,information indicating a transmission bandwidth of the second signal,information indicating whether or not to perform the detection of thesecond signal, and a virtual cell ID (for example, a value of a virtualcell ID with respect to a cell 1 (for example, a small cell 1) for whichthe second carrier type is set) may be included in a parameter relatingto the second signal.

Furthermore, a parameter relating to the measurement of the receivedpower that is based on the second signal may be transmitted as aparameter relating to the second signal. Here, a parameter forindicating whether or not the received power is measured based on thesecond signal may be included in the parameter relating to themeasurement of the received power that is based on the second signal.Moreover, in some cases, the parameter relating to the second signal isalso referred to as the information relating to the configuration of thesecond signal.

The terminal 2 that receives the parameter relating to the second signalfrom the base station 1 detects the second signal. Here, the terminal 2may transmit to the base station 1 information indicating that thesecond signal is detected (e.g. information indicating that thedetection of the second signal succeeds).

Furthermore, the base station 1 may transmit to the terminal 2 aparameter relating to the cell addition/removal (and/or a parameterrelating to cell activation/deactivation) in a state of being includedin a higher layer signal (for example, a dedicated signal). Here, theparameter (and/or the parameter relating to the cellactivation/deactivation) relating to the addition/removal of the cell(for example, the cell 1 (small cell 1) for which the second carriertype is set) for which the second carrier type is set may be transmittedas the parameter relating to the cell addition/removal (and/or theparameter relating to the cell activation/deactivation). At this time,the base station 1 may set the parameter relating to the second signalin such a manner that the parameter relating to the second signal isassociated with a cell being added. Furthermore, the base station 1 mayset the parameter relating to the measurement of the received power thatis based on the second signal in such a manner that the parameterrelating to the measurement of the received power is associated with thecell being added.

Furthermore, in the cell 1 for which the second carrier type is set (forexample, the small cell 1), the terminal 2 performs the received powermeasurement that is based on at least the second signal. Here, thesecond signal is generated (or mapped) based on the virtual cell ID (forexample, the virtual cell ID with respect to the cell 1 (small cell 1)for which the second carrier type is set) that is set using a higherlayer signal (for example, a dedicated signal).

Moreover, the base station 1 assigns the virtual cell ID (for example, avalue of the virtual cell ID with respect to a cell 2 (small cell 2) forwhich the second carrier type is set) to the terminal 2 using a higherlayer signal (for example, a dedicated signal). Here, the base station 1may set the virtual cell ID using a higher layer signal and/or thePDCCH. Furthermore, the base station 1 may transmit the virtual cell IDin a state of being included in a message relating to the handovercommand. Furthermore, the base station 1 may transmit the parameterrelating to the measurement of the received power measurement that isbased on the second signal, in a state of being included in the higherlayer signal (for example, the dedicated signal) or the message relatingto the handover command. That is, switching (reconfiguration) from thecell (for example, the small cell 1) for which the second carrier typeis set to the cell (for example, the small cell 2) for which the secondcarrier type is set is performed by re-setting the virtual cell IDwithout setting the parameter relating the cell addition/removal.Moreover, in some cases, the messages are also referred to as the RRCmessage.

Moreover, in the cell 2 (for example, the small cell 2) for which thesecond carrier type is set, the terminal 2 performs the received powermeasurement that is based on at least the second signal. Here, thesecond signal is generated (or mapped) based on the virtual cell ID (forexample, the virtual cell ID with respect to the cell 2 (small cell 2)for which the second carrier type is set) that is set using the messagerelating to the higher layer signal (for example, the dedicated signal)or the handover command.

The operation of each of the base station 1 and the terminal 2 describedabove is only an example. That is, the present embodiment is not limitedto the operation as described above, and all the same operations areincluded in the present embodiment.

In a case where pieces of information relating to configurations ofCSI-RSs in which the virtual cell IDs are set to the same value are setto be in a shared measurement ID (or a measurement object ID), thereceived power measurement may be performed using these multipleCSI-RSs.

In a case where the values of the virtual cell IDs that are set to be inthe pieces of information relating to the configurations of multipleCSI-RSs are set to the same value, the received power measurement may beperformed using these multiple CSI-RSs. In a case where the virtual cellIDs are set to different values, respectively, the received powermeasurement may be performed using these multiple CSI-RSs independently.

In a case where the cell that is set to the second carrier type isdeactivated, based on a first measurement period, the terminal 2performs the received power measurement that is based on the secondsignal. Furthermore, in a case where the cell that is set to the secondcarrier type is activated, based on a second measurement period, theterminal 2 performs the received power measurement that is based on thesecond signal. For example, being deactivated means that datacommunication is not performed between the base station and theterminal.

As illustrated in FIG. 4, the terminal 2 can set a received powermeasurement subframe that is based on the first measurement period, andcan set a received power measurement subframe that is based on thesecond measurement period. With the higher layer signaling, the basestation 1 notifies these pieces of configuration information. To be moreprecise, according to whether the cell that is set to the second carriertype is deactivated or activated, the terminal 2 can switch themeasurement period and switch the timing for performing the receivedpower measurement. While reducing power consumption indispensable forthe received power measurement by performing the received powermeasurement at long time intervals with respect to the cell that doesnot perform the data communication, the terminal 2 can perform suitablescheduling in a case where the data communication is performed toperiodically report a result of the measurement to the base station 1.

Furthermore, in a case where, based on the first measurement period, thereceived power measurement that is based on the second signal isperformed, when a predetermined measurement time configured from thefirst measurement period elapses, the terminal 2 reports to the higherlayer the result of the measurement of the received power that is basedon the second signal, and transmits such report information to the basestation 1. Each terminal, in advance, reports to the base station 1 theinformation relating to the result of the measurement with respect tothe deactivated cell (to be more precise, the cell that does not performthe data communication). Thus, the base station 1 can perform suitablescheduling when a cell switches from a deactivated state to an activatedstate.

Furthermore, in a case where, based on the second measurement period,the received power measurement that is based on the second signal isperformed, when a predetermined condition (a measurement report event)that is included in the information relating to the result of themeasurement is satisfied, the terminal 2 reports to the higher layer theresult of the measurement of the received power that is based on thesecond signal, and transmits the report information to the base station1. Furthermore, at this time, the terminal 2 may periodically report tothe higher layer the result of the measurement of the received powerthat is based on the second signal, and may transmit the reportinformation to the base station 1.

Here, referring to FIG. 3, according to the third embodiment, theinstruction information that a predetermined carrier type is not set fora certain cell is described as being included in the condition A.Furthermore, the instruction information that the first carrier type isset for a certain cell is included in the condition A. Furthermore, theinstruction information that a predetermined configuration(corresponding to the first carrier type) is transmitted to a certaincell is included in the condition A. The instruction information that apredetermined carrier type is set for a certain cell is included in thecondition B. Furthermore, the instruction information that the secondcarrier type is set for a certain cell is included in the condition B.Furthermore, the instruction information that a predeterminedconfiguration (corresponding to the second carrier type) is transmittedto a certain cell is included in the condition B. Furthermore, theinstruction information that a predetermined configuration(corresponding to the first carrier type) is not transmitted to acertain cell is included in the condition B.

By setting specific information, receiving processing of a specificphysical channel or physical signal is not performed. Thus, it ispossible to suppress power consumption indispensable for the receivingprocessing.

Moreover, according to each of the embodiments described above, theterminal 2 may report to the base station 1 the result of themeasurement of the received power that is based on the second signal.The terminal 2 may periodically make a report. Furthermore, in a casewhere a certain condition is satisfied, the terminal 2 may make areport.

According to each of the embodiments described above, in a case wherethe received power that is based on the second signal is measured, theterminal 2 may perform the transmission power control of the uplinksignal based on the received power. Furthermore, the terminal 2 maydetermine the downlink path loss based on the received power.

Moreover, according to each of the embodiments, the resource element orthe resource block is described above as being used as a unit formapping information data signal, control information signal, the PDSCH,the PDCCH and a reference signal, and the subframe or the radio frame isdescribed above as being used as a unit of transmission in a timedomain, but the present invention is not limited to this. Even if,instead of these, domains and time units are used that are configuredfrom an arbitrary frequency and time, respectively, the same effect canbe obtained. Moreover, according to each of the embodiments describedabove, the case where the demodulation is performed using RS that isprocessed in a precoded manner is described, and for description, a portthat is equivalent to an MIMO layer is used as a port corresponding toRS that is processed in a precoded manner, but the present invention isnot limited to this. In addition, the same effect can be obtained byapplying the present invention to ports that correspond to differentreference signals, respectively. For example, unprecoded (non-precoded)can be used instead of precoded RS, and a port that is equivalent to anoutput terminal after the precoding processing, or a port that isequivalent to a physical antenna (or a combination of physical antennas)can be used.

Moreover, according to each of the embodiments described above, theuplink transmission power control is transmission power control ofuplink physical channels (the PUSCH, the PUCCH, the PRACH, and the SRS),and the transmission power control includes switching and/or (re-)configuration of various parameters that are used in configurations ofthe transmission power of each of various uplink physical channels.

Moreover, according to each of the embodiments described above, the basestation 1 may possibly set multiple virtual cell IDs for one terminal 2.For example, the base station 1 and a network including at least onebase station 1 may possibly set the virtual cell ID independently forevery physical channel/physical signal. Furthermore, multiple virtualcell IDs may possibly be set for one physical channel/physical signal.To be more precise, the virtual cell ID may possibly be set for everypiece of information relating to the configuration of each physicalchannel/physical signal. Furthermore, with the multiple physicalchannels/physical signals, the virtual cell ID may be shared.

A program running on the base station 1 and the terminal 2 according tothe present invention is a program (a program for causing a computer tooperate) that controls a CPU and the like in such a manner as to realizethe function according to the embodiment of the present invention. Then,the information that is handled in these apparatuses is temporarilystored in a RAM while being processed. Thereafter, the information isstored in various ROMs or HDDs, and whenever necessary, is read by theCPU to be modified or written. As a recording medium on which to storethe program, among a semiconductor medium (for example, a ROM, anonvolatile memory card, and the like), an optical storage medium (forexample, a DVD, a MO, a MD, a CD, a BD, and the like), a magneticstorage medium (for example, a magnetic tape, a flexible disk, and thelike), and the like, any one may be possible. Furthermore, in somecases, the function according to the embodiment described above isrealized by running the loaded program, and in addition, the functionaccording to the present invention is realized by performing processingin conjunction with an operating system or other application programs,based on an instruction from the program.

Furthermore, in a case where the programs are distributed on the market,the program stored on a portable recording medium can be distributed orthe program can be transmitted to a server computer that connectsthrough a network such as the Internet. In this case, a storage devicein the server computer also is included in the present invention.Furthermore, some or all portions of the base station 1 and the terminal2 according to the embodiment described above may be realized as an LSIthat is a typical integrated circuit. Each functional block of the basestation 1 and the terminal 2 may be individually built into a chip, andsome or all functional blocks may be integrated into a chip.Furthermore, a technique of the integrated circuit is not limited to theLSI, and an integrated circuit for the functional block may be realizedwith a dedicated circuit or a general-purpose processor. Furthermore, ifwith advances in a semiconductor technology, an integrated circuittechnology that substitutes for the LSI appears, it is also possible touse an integrated circuit to which such a technology is applied.

Moreover, the present invention is not limited to these embodimentsdescribed above. Furthermore, it does not go without saying that theterminal apparatus 1 according to the present invention is not to theapplication to the mobile station, but can be applied also to afixed-type electronic apparatus that is installed indoors or outdoors,or a stationary-type electronic apparatus, for example, an AV apparatus,a kitchen apparatus, a cleaning or washing machine, an air-conditioningapparatus, an office apparatus, a vending machine, or other householdapparatuses.

The embodiments of the invention are described in detail above referringto the drawings, but the specific configuration is not limited to theembodiments and includes an amendment to a design that falls within ascope not deviating from the gist of the present invention. Furthermore,various modifications are possible within the scope of the presentinvention defined by claims, and embodiments that are made by suitablycombining technical means disclosed according to the differentembodiments are also included in the technical scope of the presentinvention. Furthermore, a configuration in which a constituent elementthat achieves the same effect is substituted for one that is mentionedaccording to each of the embodiments is also included in the technicalscope of the present invention.

INDUSTRIAL APPLICABILITY

The present invention is suitable for use in a radio base stationapparatus, a radio terminal apparatus, a radio communication system, ora radio communication method.

DESCRIPTION OF REFERENCE NUMERALS

1 BASE STATION

2 TERMINAL

101 HIGHER LAYER PROCESSING UNIT

103 CONTROL UNIT

105 RECEPTION UNIT

107 TRANSMISSION UNIT

109 CHANNEL MEASUREMENT UNIT

111 TRANSMIT AND RECEIVE ANTENNA UNIT

1011 RADIO RESOURCE CONTROL UNIT

1013 MEASUREMENT SETTING UNIT

1015 TRANSMISSION POWER SETTING UNIT

1051 DECODING UNIT

1053 DEMODULATION UNIT

1055 DEMULTIPLEXING UNIT

1057 RADIO RECEPTION UNIT

1071 CODING UNIT

1073 MODULATION UNIT

1075 MULTIPLEXING UNIT

1077 RADIO TRANSMISSION UNIT

1079 DOWNLINK REFERENCE SIGNAL GENERATION UNIT

201 HIGHER LAYER PROCESSING UNIT

203 CONTROL UNIT

205 RECEPTION UNIT

207 TRANSMISSION UNIT

209 CHANNEL MEASUREMENT UNIT

211 TRANSMIT AND RECEIVE ANTENNA

2011 RADIO RESOURCE CONTROL UNIT

2013 MEASUREMENT CONTROL UNIT

2015 TRANSMISSION POWER CONTROL UNIT

2051 DECODING UNIT

2053 DEMODULATION UNIT

2055 DEMULTIPLEXING UNIT

2057 RADIO RECEPTION UNIT

2071 CODING UNIT

2073 MODULATION UNIT

2075 MULTIPLEXING UNIT

2077 RADIO TRANSMISSION UNIT

2079 UPLINK REFERENCE SIGNAL GENERATION UNIT

The invention claimed is:
 1. A terminal apparatus comprising: areception circuitry configured to perform, for a certain cell, ameasurement of a first signal including a primary synchronizationsignal, a secondary synchronization signal and cell-specific signals ina first period in a case that the first period is configured, wherein,in a case that a configuration of channel state information referencesignals is configured as a part of a configuration of the first signal,the reception circuitry is configured to perform, for the certain cell,that is set to a predetermined type being first type, a reference signalreceived power measurement based on the channel state informationreference signals in the first duration, and the reception circuitry isconfigured to perform, for the certain cell that is set to thepredetermined type being second type, the reference signal receivedpower measurement based on the channel state information referencesignals in a second duration.
 2. A base station apparatus comprising: atransmission circuitry configured to transmit, for a certain cell, afirst signal including a primary synchronization signal, a secondarysynchronization signal and cell-specific reference signals in a firstperiod in a case that information relating to a configuration of thefirst period is transmitted to a terminal apparatus, wherein, in a casethat a configuration of channel state information reference signals isconfigured as a part of a configuration of the first signal, thetransmission circuitry is configured to transmit, for the certain cellthat is set to a predetermined type being first type, channel stateinformation reference signals in a first duration, and the transmissioncircuitry is configured to transmit, for the certain cell that is set tothe predetermined type being second type, the channel state informationreference signals in a second duration.
 3. A method for a terminalapparatus, the method comprising: performing, for a certain cell, ameasurement of a first signal including a primary synchronizationsignal, a secondary synchronization signal and cell-specific signals ina first period in a case that the first period is configured, wherein ina case that a configuration of channel state information referencesignals is configured as a part of a configuration of the first signal,performing, for the certain cell that is set to a predetermined typebeing first type, a reference signal received power measurement based onthe channel state information reference signals in a first duration, andperforming, for the certain cell that is set to the predetermined typebeing second type, the reference signal received power measurement basedon the channel state information reference signals in a second duration.